The parenteral administration of medical liquids is an established clinical practice. The liquids are administered particularly intravenously, and the practice is used extensively as an integral part of the daily treatment of medical and surgical patients. The liquids commonly administered include blood and blood substitutes, dextrose solution, electrolyte solution, and saline. Generally, the liquids are administered from an intravenous delivery system having a container suspended above the patient, with the liquid flowing through a catheter hypodermic needle set to the patient.
The administration of liquids intravenously is a valuable and important component that contributes to the optimal care of the patient; however, it does not provide a satisfactory means and method for administering concomitantly therewith a beneficial agent. Presently, a beneficial agent is administered intravenously by (1) temporarily removing the intravenous system and halting the flow of liquid, and then intravenously administering the agent to the patient followed by reinserting the intravenous system into the patient; (2) the agent is added to the liquid in the container and then carried by the flow of the liquid to the patient; (3) agent is added to a liquid in a separate container called a partial fill that is connected to the primary intravenous line through which line the agent is carried by the flow of liquid to the patient; (4) an agent is contained in a piggyback vial into which is introduced an intravenous fluid, with the vital subsequently connected to the primary line through which the drug is administered to the patient; or (5) the agent is administered by a pump that exerts a force on a liquid containing agent for intravenously adminstering the liquid containing the agent. While these techniques are used, they have major disadvantages. For example, the administration of an agent through repeated insertion of a needle leads to unnecessary pain and trauma, they require separate connections for joining the primary intravenous line which further complicates intravenous administration, the use of pumps can produce pressures that can vary at the delivery site and the pressure can give rise to thrombosis, the rate of agent delivery to the patient often is unknown as it is not rate-controlled agent delivery but dependent on the flow of fluid, and they often require preformulation of the agent medication by the hospital pharmacist or nurse. In view of this presentation, it is immediately apparent a critical need exists in the field of intravenous delivery for a hospital acceptable and dependable manufacture and method for administering a beneficial agent at a controlled rate in intravenous delivery systems.